noun. Espionage undertaken to detect and counteract enemy espionage.

noun. All those activities undertaken to neutralize or exploit the espionage activities of another nation or an enemy

noun. spying on the spies

"JACOBSON: Well, I don't know specifically, but I will say that all members of the U.S. military are trained in what's called counterespionage, counterintelligence activities, in terms of being able to look at suspicious activities, things that may not seem right, such as someone who doesn't have access to classified information seeking out that information."

counterintelligence  

espionage  

antiterrorism  backstabbing  basedin  brass-handled  commonweal  

bugging  cloak-and-dagger work  counterintelligence  counterintelligence  electronic surveillance